Red Hat Bugzilla – Bug 351781
X ignoring Modeline, VertRefresh and HorizSync options in xorg.conf
Last modified: 2012-03-09 17:40:29 EST
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Description of problem:
I have a customer who is having problems getting widescreen resolutions to work on their widescreen monitor. It displays non-widescreen resolutions ok leaving 2 black sections down either side. Graphics card is SiS, monitor is LG L204WT and using RHEL5. I've attached xorg.conf and Xorg.0.log files. xorg.conf files generated by system-config-display (various switches tried) and X -configure haven't had any impact.
Interestingly I got him to run 'xvidtune' and this allowed the screen to be filled. Customer saved the settings generated by xvidtune in xorg.conf but when X restarts the settings are ignored. He has to run xvidtune every time to get the screen filled again. I can see similar settings being automatically detected in the Xorg.0.log file.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Start X. Output is displayed incorrectly
2. Use 'xvidtune' to adjust the display to fill the screen. Have xvidtune write out current video settings.
3. Put video settings in xorg.conf
4. Restart X. Output reverts to previous settings.
5. xvidtune has to be re-run each time X starts.
Special Modeline, VertRefresh and HorizSync settings in xorg.conf are ignored by X. Output is displayed with 2 black sections down either side of the screen regardless of settings.
Output should fill whole screen, preferably without having to fiddle with video mode settings. It should 'just work' after setting the resolution in system-config-display or equivalent.
Sent an email to tech-list on 25/10/07 about this and Matěj Cepl recommended I file a bugzilla.
Created attachment 237031 [details]
Current xorg.conf with special settings
Created attachment 237041 [details]
Log seems to show that video modes are automatically detected. However they aren't used.
sis driver almost certainly not going to get updated in RHEL5 at this point. If this is still an issue in RHEL6, please reopen and update the product version to match.